给水超滤膜系统中曝气对膜通量的影响及其机理研究

Study on mechanisms and impacts of aeration on the membrane flux in drinking water ultrafiltration membrane treatment

通过系列试验探讨了淹没式给水超滤膜系统中曝气对膜通量的影响及其机理,结果表明:淹没式给水超滤膜系统中膜通量随时间和过滤水量的变化均由快、慢两个指数衰减模式共同组成,其衰减过程符合相似的衰减方程式;曝气可有效改变膜表面的流体流态,提高膜通量,最大假想稳定态膜通量及其最小衰减系数均在曝气条件下达到;曝气强度对膜通量改善影响明显,曝气强度越大,膜通量改善程度越强,但超过一定曝气强度后曝气强度对膜通量改善的影响甚微。

This paper studied the influence of aeration in the submerged drinking water ultrafihration membrane system on membrane flux and its mechanisms. The results showed that： the variance of the membrane flux in the submerged drinking water ultrafiltration membrane system depending on time and permeated flux was composed of rapid and slow exponential evanescent modes, and the evanescent processes matched the similar evanescent equation; aeration could efficiently improve the fluid flow pattern on the membrane surface, increase membrane flux, and realize the maximum theoretical stable membrane flux and the minimum evanescent coefficient; the influence of aeration on mem- brane flux was obvious, the more aeration intensity the better improvement on membrane flux, but the influence became indifferent when the aeration intensity was above certain.